Pigments offer several advantages over water-soluble dyes when it comes to inkjet inks. Pigments may exhibit at least one of greater light resistance, water resistance, optical density and edge acuity than water-soluble dyes. Unfortunately, pigments also have a greater propensity to settle during storage, thus initially limiting their use in inkjet inks. The advent of media mills to grind pigment particles to sub-micron level combined with chemical additives for colloidal stability has propelled the use of pigment dispersions in inkjet ink formulations. However, chemical additives can increase the viscosity of a dispersion such that it becomes difficult to jet the ink from the small orifices in an inkjet printhead. Moreover, chemical additives can add significant cost to the preparation of inkjet inks and are therefore economically unfavorable as well. A need remains for improved ink compositions, especially for use in inkjet printers, which overcome the problems typically associated with current dye-based systems and pigment systems employing chemical additives.